]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/recovery.c
Update bcachefs sources to 84f132d569 bcachefs: fsck: Break walk_inode() up into...
[bcachefs-tools-debian] / libbcachefs / recovery.c
index 80befab87f2d8288d3a35fa1d739bc8867f55be4..09c9d4058f829d4e7395712146074ebd7cab7f3c 100644 (file)
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include "bcachefs.h"
+#include "backpointers.h"
 #include "bkey_buf.h"
 #include "alloc_background.h"
 #include "btree_gc.h"
@@ -10,6 +11,7 @@
 #include "buckets.h"
 #include "dirent.h"
 #include "ec.h"
+#include "errcode.h"
 #include "error.h"
 #include "fs-common.h"
 #include "fsck.h"
@@ -86,9 +88,9 @@ static inline struct journal_key *idx_to_key(struct journal_keys *keys, size_t i
        return keys->d + idx_to_pos(keys, idx);
 }
 
-size_t bch2_journal_key_search(struct journal_keys *keys,
-                              enum btree_id id, unsigned level,
-                              struct bpos pos)
+static size_t __bch2_journal_key_search(struct journal_keys *keys,
+                                       enum btree_id id, unsigned level,
+                                       struct bpos pos)
 {
        size_t l = 0, r = keys->nr, m;
 
@@ -106,48 +108,69 @@ size_t bch2_journal_key_search(struct journal_keys *keys,
        BUG_ON(l &&
               __journal_key_cmp(id, level, pos, idx_to_key(keys, l - 1)) <= 0);
 
-       return idx_to_pos(keys, l);
+       return l;
 }
 
-struct bkey_i *bch2_journal_keys_peek(struct bch_fs *c, enum btree_id btree_id,
-                                     unsigned level, struct bpos pos)
+static size_t bch2_journal_key_search(struct journal_keys *keys,
+                                     enum btree_id id, unsigned level,
+                                     struct bpos pos)
+{
+       return idx_to_pos(keys, __bch2_journal_key_search(keys, id, level, pos));
+}
+
+struct bkey_i *bch2_journal_keys_peek_upto(struct bch_fs *c, enum btree_id btree_id,
+                                          unsigned level, struct bpos pos,
+                                          struct bpos end_pos, size_t *idx)
 {
        struct journal_keys *keys = &c->journal_keys;
-       size_t idx = bch2_journal_key_search(keys, btree_id, level, pos);
+       unsigned iters = 0;
+       struct journal_key *k;
+search:
+       if (!*idx)
+               *idx = __bch2_journal_key_search(keys, btree_id, level, pos);
+
+       while ((k = *idx < keys->nr ? idx_to_key(keys, *idx) : NULL)) {
+               if (__journal_key_cmp(btree_id, level, end_pos, k) < 0)
+                       return NULL;
+
+               if (__journal_key_cmp(btree_id, level, pos, k) <= 0 &&
+                   !k->overwritten)
+                       return k->k;
 
-       while (idx < keys->size &&
-              keys->d[idx].overwritten) {
-               idx++;
-               if (idx == keys->gap)
-                       idx += keys->size - keys->nr;
+               (*idx)++;
+               iters++;
+               if (iters == 10) {
+                       *idx = 0;
+                       goto search;
+               }
        }
 
-       if (idx < keys->size &&
-           keys->d[idx].btree_id == btree_id &&
-           keys->d[idx].level == level)
-               return keys->d[idx].k;
        return NULL;
 }
 
+struct bkey_i *bch2_journal_keys_peek_slot(struct bch_fs *c, enum btree_id btree_id,
+                                          unsigned level, struct bpos pos)
+{
+       size_t idx = 0;
+
+       return bch2_journal_keys_peek_upto(c, btree_id, level, pos, pos, &idx);
+}
+
 static void journal_iters_fix(struct bch_fs *c)
 {
        struct journal_keys *keys = &c->journal_keys;
        /* The key we just inserted is immediately before the gap: */
-       struct journal_key *n = &keys->d[keys->gap - 1];
        size_t gap_end = keys->gap + (keys->size - keys->nr);
        struct btree_and_journal_iter *iter;
 
        /*
-        * If an iterator points one after the key we just inserted,
-        * and the key we just inserted compares >= the iterator's position,
-        * decrement the iterator so it points at the key we just inserted:
+        * If an iterator points one after the key we just inserted, decrement
+        * the iterator so it points at the key we just inserted - if the
+        * decrement was unnecessary, bch2_btree_and_journal_iter_peek() will
+        * handle that:
         */
        list_for_each_entry(iter, &c->journal_iters, journal.list)
-               if (iter->journal.idx == gap_end &&
-                   iter->last &&
-                   iter->b->c.btree_id == n->btree_id &&
-                   iter->b->c.level    == n->level &&
-                   bpos_cmp(n->k->k.p, iter->unpacked.p) >= 0)
+               if (iter->journal.idx == gap_end)
                        iter->journal.idx = keys->gap - 1;
 }
 
@@ -199,14 +222,13 @@ int bch2_journal_key_insert_take(struct bch_fs *c, enum btree_id id,
                struct journal_keys new_keys = {
                        .nr                     = keys->nr,
                        .size                   = max_t(size_t, keys->size, 8) * 2,
-                       .journal_seq_base       = keys->journal_seq_base,
                };
 
-               new_keys.d = kvmalloc(sizeof(new_keys.d[0]) * new_keys.size, GFP_KERNEL);
+               new_keys.d = kvmalloc_array(new_keys.size, sizeof(new_keys.d[0]), GFP_KERNEL);
                if (!new_keys.d) {
                        bch_err(c, "%s: error allocating new key array (size %zu)",
                                __func__, new_keys.size);
-                       return -ENOMEM;
+                       return -BCH_ERR_ENOMEM_journal_key_insert;
                }
 
                /* Since @keys was full, there was no gap: */
@@ -244,7 +266,7 @@ int bch2_journal_key_insert(struct bch_fs *c, enum btree_id id,
 
        n = kmalloc(bkey_bytes(&k->k), GFP_KERNEL);
        if (!n)
-               return -ENOMEM;
+               return -BCH_ERR_ENOMEM_journal_key_insert;
 
        bkey_copy(n, k);
        ret = bch2_journal_key_insert_take(c, id, level, n);
@@ -273,34 +295,34 @@ void bch2_journal_key_overwritten(struct bch_fs *c, enum btree_id btree,
        if (idx < keys->size &&
            keys->d[idx].btree_id       == btree &&
            keys->d[idx].level          == level &&
-           !bpos_cmp(keys->d[idx].k->k.p, pos))
+           bpos_eq(keys->d[idx].k->k.p, pos))
                keys->d[idx].overwritten = true;
 }
 
-static struct bkey_i *bch2_journal_iter_peek(struct journal_iter *iter)
+static void bch2_journal_iter_advance(struct journal_iter *iter)
+{
+       if (iter->idx < iter->keys->size) {
+               iter->idx++;
+               if (iter->idx == iter->keys->gap)
+                       iter->idx += iter->keys->size - iter->keys->nr;
+       }
+}
+
+struct bkey_s_c bch2_journal_iter_peek(struct journal_iter *iter)
 {
        struct journal_key *k = iter->keys->d + iter->idx;
 
-       while (k < iter->keys->d + iter->keys->nr &&
+       while (k < iter->keys->d + iter->keys->size &&
               k->btree_id      == iter->btree_id &&
               k->level         == iter->level) {
                if (!k->overwritten)
-                       return k->k;
+                       return bkey_i_to_s_c(k->k);
 
-               iter->idx++;
+               bch2_journal_iter_advance(iter);
                k = iter->keys->d + iter->idx;
        }
 
-       return NULL;
-}
-
-static void bch2_journal_iter_advance(struct journal_iter *iter)
-{
-       if (iter->idx < iter->keys->size) {
-               iter->idx++;
-               if (iter->idx == iter->keys->gap)
-                       iter->idx += iter->keys->size - iter->keys->nr;
-       }
+       return bkey_s_c_null;
 }
 
 static void bch2_journal_iter_exit(struct journal_iter *iter)
@@ -332,71 +354,49 @@ static void bch2_journal_iter_advance_btree(struct btree_and_journal_iter *iter)
 
 void bch2_btree_and_journal_iter_advance(struct btree_and_journal_iter *iter)
 {
-       switch (iter->last) {
-       case none:
-               break;
-       case btree:
-               bch2_journal_iter_advance_btree(iter);
-               break;
-       case journal:
-               bch2_journal_iter_advance(&iter->journal);
-               break;
-       }
-
-       iter->last = none;
+       if (bpos_eq(iter->pos, SPOS_MAX))
+               iter->at_end = true;
+       else
+               iter->pos = bpos_successor(iter->pos);
 }
 
 struct bkey_s_c bch2_btree_and_journal_iter_peek(struct btree_and_journal_iter *iter)
 {
-       struct bkey_s_c ret;
+       struct bkey_s_c btree_k, journal_k, ret;
+again:
+       if (iter->at_end)
+               return bkey_s_c_null;
 
-       while (1) {
-               struct bkey_s_c btree_k         =
-                       bch2_journal_iter_peek_btree(iter);
-               struct bkey_s_c journal_k       =
-                       bkey_i_to_s_c(bch2_journal_iter_peek(&iter->journal));
-
-               if (btree_k.k && journal_k.k) {
-                       int cmp = bpos_cmp(btree_k.k->p, journal_k.k->p);
+       while ((btree_k = bch2_journal_iter_peek_btree(iter)).k &&
+              bpos_lt(btree_k.k->p, iter->pos))
+               bch2_journal_iter_advance_btree(iter);
 
-                       if (!cmp)
-                               bch2_journal_iter_advance_btree(iter);
+       while ((journal_k = bch2_journal_iter_peek(&iter->journal)).k &&
+              bpos_lt(journal_k.k->p, iter->pos))
+               bch2_journal_iter_advance(&iter->journal);
 
-                       iter->last = cmp < 0 ? btree : journal;
-               } else if (btree_k.k) {
-                       iter->last = btree;
-               } else if (journal_k.k) {
-                       iter->last = journal;
-               } else {
-                       iter->last = none;
-                       return bkey_s_c_null;
-               }
+       ret = journal_k.k &&
+               (!btree_k.k || bpos_le(journal_k.k->p, btree_k.k->p))
+               ? journal_k
+               : btree_k;
 
-               ret = iter->last == journal ? journal_k : btree_k;
+       if (ret.k && iter->b && bpos_gt(ret.k->p, iter->b->data->max_key))
+               ret = bkey_s_c_null;
 
-               if (iter->b &&
-                   bpos_cmp(ret.k->p, iter->b->data->max_key) > 0) {
-                       iter->journal.idx = iter->journal.keys->nr;
-                       iter->last = none;
-                       return bkey_s_c_null;
+       if (ret.k) {
+               iter->pos = ret.k->p;
+               if (bkey_deleted(ret.k)) {
+                       bch2_btree_and_journal_iter_advance(iter);
+                       goto again;
                }
-
-               if (!bkey_deleted(ret.k))
-                       break;
-
-               bch2_btree_and_journal_iter_advance(iter);
+       } else {
+               iter->pos = SPOS_MAX;
+               iter->at_end = true;
        }
 
        return ret;
 }
 
-struct bkey_s_c bch2_btree_and_journal_iter_next(struct btree_and_journal_iter *iter)
-{
-       bch2_btree_and_journal_iter_advance(iter);
-
-       return bch2_btree_and_journal_iter_peek(iter);
-}
-
 void bch2_btree_and_journal_iter_exit(struct btree_and_journal_iter *iter)
 {
        bch2_journal_iter_exit(&iter->journal);
@@ -414,6 +414,8 @@ void __bch2_btree_and_journal_iter_init_node_iter(struct btree_and_journal_iter
        iter->node_iter = node_iter;
        bch2_journal_iter_init(c, &iter->journal, b->c.btree_id, b->c.level, pos);
        INIT_LIST_HEAD(&iter->journal.list);
+       iter->pos = b->data->min_key;
+       iter->at_end = false;
 }
 
 /*
@@ -474,15 +476,34 @@ void bch2_journal_keys_free(struct journal_keys *keys)
        keys->nr = keys->gap = keys->size = 0;
 }
 
+static void __journal_keys_sort(struct journal_keys *keys)
+{
+       struct journal_key *src, *dst;
+
+       sort(keys->d, keys->nr, sizeof(keys->d[0]), journal_sort_key_cmp, NULL);
+
+       src = dst = keys->d;
+       while (src < keys->d + keys->nr) {
+               while (src + 1 < keys->d + keys->nr &&
+                      src[0].btree_id  == src[1].btree_id &&
+                      src[0].level     == src[1].level &&
+                      bpos_eq(src[0].k->k.p, src[1].k->k.p))
+                       src++;
+
+               *dst++ = *src++;
+       }
+
+       keys->nr = dst - keys->d;
+}
+
 static int journal_keys_sort(struct bch_fs *c)
 {
        struct genradix_iter iter;
        struct journal_replay *i, **_i;
        struct jset_entry *entry;
-       struct bkey_i *k, *_n;
+       struct bkey_i *k;
        struct journal_keys *keys = &c->journal_keys;
-       struct journal_key *src, *dst;
-       size_t nr_keys = 0;
+       size_t nr_keys = 0, nr_read = 0;
 
        genradix_for_each(&c->journal_entries, iter, _i) {
                i = *_i;
@@ -490,10 +511,7 @@ static int journal_keys_sort(struct bch_fs *c)
                if (!i || i->ignore)
                        continue;
 
-               if (!keys->journal_seq_base)
-                       keys->journal_seq_base = le64_to_cpu(i->j.seq);
-
-               for_each_jset_key(k, _n, entry, &i->j)
+               for_each_jset_key(k, entry, &i->j)
                        nr_keys++;
        }
 
@@ -502,9 +520,22 @@ static int journal_keys_sort(struct bch_fs *c)
 
        keys->size = roundup_pow_of_two(nr_keys);
 
-       keys->d = kvmalloc(sizeof(keys->d[0]) * keys->size, GFP_KERNEL);
-       if (!keys->d)
-               return -ENOMEM;
+       keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
+       if (!keys->d) {
+               bch_err(c, "Failed to allocate buffer for sorted journal keys (%zu keys); trying slowpath",
+                       nr_keys);
+
+               do {
+                       keys->size >>= 1;
+                       keys->d = kvmalloc_array(keys->size, sizeof(keys->d[0]), GFP_KERNEL);
+               } while (!keys->d && keys->size > nr_keys / 8);
+
+               if (!keys->d) {
+                       bch_err(c, "Failed to allocate %zu size buffer for sorted journal keys; exiting",
+                               keys->size);
+                       return -BCH_ERR_ENOMEM_journal_keys_sort;
+               }
+       }
 
        genradix_for_each(&c->journal_entries, iter, _i) {
                i = *_i;
@@ -512,34 +543,35 @@ static int journal_keys_sort(struct bch_fs *c)
                if (!i || i->ignore)
                        continue;
 
-               BUG_ON(le64_to_cpu(i->j.seq) - keys->journal_seq_base > U32_MAX);
+               cond_resched();
+
+               for_each_jset_key(k, entry, &i->j) {
+                       if (keys->nr == keys->size) {
+                               __journal_keys_sort(keys);
+
+                               if (keys->nr > keys->size * 7 / 8) {
+                                       bch_err(c, "Too many journal keys for slowpath; have %zu compacted, buf size %zu, processed %zu/%zu",
+                                               keys->nr, keys->size, nr_read, nr_keys);
+                                       return -BCH_ERR_ENOMEM_journal_keys_sort;
+                               }
+                       }
 
-               for_each_jset_key(k, _n, entry, &i->j)
                        keys->d[keys->nr++] = (struct journal_key) {
                                .btree_id       = entry->btree_id,
                                .level          = entry->level,
                                .k              = k,
-                               .journal_seq    = le64_to_cpu(i->j.seq) -
-                                       keys->journal_seq_base,
+                               .journal_seq    = le64_to_cpu(i->j.seq),
                                .journal_offset = k->_data - i->j._data,
                        };
-       }
-
-       sort(keys->d, keys->nr, sizeof(keys->d[0]), journal_sort_key_cmp, NULL);
-
-       src = dst = keys->d;
-       while (src < keys->d + keys->nr) {
-               while (src + 1 < keys->d + keys->nr &&
-                      src[0].btree_id  == src[1].btree_id &&
-                      src[0].level     == src[1].level &&
-                      !bpos_cmp(src[0].k->k.p, src[1].k->k.p))
-                       src++;
 
-               *dst++ = *src++;
+                       nr_read++;
+               }
        }
 
-       keys->nr = dst - keys->d;
+       __journal_keys_sort(keys);
        keys->gap = keys->nr;
+
+       bch_verbose(c, "Journal keys: %zu read, %zu after sorting and compacting", nr_keys, keys->nr);
        return 0;
 }
 
@@ -548,7 +580,8 @@ static int journal_keys_sort(struct bch_fs *c)
 static void replay_now_at(struct journal *j, u64 seq)
 {
        BUG_ON(seq < j->replay_journal_seq);
-       BUG_ON(seq > j->replay_journal_seq_end);
+
+       seq = min(seq, j->replay_journal_seq_end);
 
        while (j->replay_journal_seq < seq)
                bch2_journal_pin_put(j, j->replay_journal_seq++);
@@ -591,7 +624,7 @@ static int journal_sort_seq_cmp(const void *_l, const void *_r)
        return cmp_int(l->journal_seq, r->journal_seq);
 }
 
-static int bch2_journal_replay(struct bch_fs *c)
+static int bch2_journal_replay(struct bch_fs *c, u64 start_seq, u64 end_seq)
 {
        struct journal_keys *keys = &c->journal_keys;
        struct journal_key **keys_sorted, *k;
@@ -604,7 +637,7 @@ static int bch2_journal_replay(struct bch_fs *c)
 
        keys_sorted = kvmalloc_array(sizeof(*keys_sorted), keys->nr, GFP_KERNEL);
        if (!keys_sorted)
-               return -ENOMEM;
+               return -BCH_ERR_ENOMEM_journal_replay;
 
        for (i = 0; i < keys->nr; i++)
                keys_sorted[i] = &keys->d[i];
@@ -613,16 +646,19 @@ static int bch2_journal_replay(struct bch_fs *c)
             sizeof(keys_sorted[0]),
             journal_sort_seq_cmp, NULL);
 
-       if (keys->nr)
-               replay_now_at(j, keys->journal_seq_base);
+       if (keys->nr) {
+               ret = bch2_journal_log_msg(c, "Starting journal replay (%zu keys in entries %llu-%llu)",
+                                          keys->nr, start_seq, end_seq);
+               if (ret)
+                       goto err;
+       }
 
        for (i = 0; i < keys->nr; i++) {
                k = keys_sorted[i];
 
                cond_resched();
 
-               if (!k->allocated)
-                       replay_now_at(j, keys->journal_seq_base + k->journal_seq);
+               replay_now_at(j, k->journal_seq);
 
                ret = bch2_trans_do(c, NULL, NULL,
                                    BTREE_INSERT_LAZY_RW|
@@ -632,8 +668,8 @@ static int bch2_journal_replay(struct bch_fs *c)
                                     : 0),
                             bch2_journal_replay_key(&trans, k));
                if (ret) {
-                       bch_err(c, "journal replay: error %d while replaying key at btree %s level %u",
-                               ret, bch2_btree_ids[k->btree_id], k->level);
+                       bch_err(c, "journal replay: error while replaying key at btree %s level %u: %s",
+                               bch2_btree_ids[k->btree_id], k->level, bch2_err_str(ret));
                        goto err;
                }
        }
@@ -646,9 +682,12 @@ static int bch2_journal_replay(struct bch_fs *c)
        ret = bch2_journal_error(j);
 
        if (keys->nr && !ret)
-               bch2_journal_log_msg(&c->journal, "journal replay finished");
+               bch2_journal_log_msg(c, "journal replay finished");
 err:
        kvfree(keys_sorted);
+
+       if (ret)
+               bch_err_fn(c, ret);
        return ret;
 }
 
@@ -860,18 +899,18 @@ static int verify_superblock_clean(struct bch_fs *c,
                if (k1)
                        bch2_bkey_val_to_text(&buf1, c, bkey_i_to_s_c(k1));
                else
-                       pr_buf(&buf1, "(none)");
+                       prt_printf(&buf1, "(none)");
 
                if (k2)
                        bch2_bkey_val_to_text(&buf2, c, bkey_i_to_s_c(k2));
                else
-                       pr_buf(&buf2, "(none)");
+                       prt_printf(&buf2, "(none)");
 
                mustfix_fsck_err_on(!k1 || !k2 ||
                                    IS_ERR(k1) ||
                                    IS_ERR(k2) ||
                                    k1->k.u64s != k2->k.u64s ||
-                                   memcmp(k1, k2, bkey_bytes(k1)) ||
+                                   memcmp(k1, k2, bkey_bytes(&k1->k)) ||
                                    l1 != l2, c,
                        "superblock btree root %u doesn't match journal after clean shutdown\n"
                        "sb:      l=%u %s\n"
@@ -905,7 +944,7 @@ static struct bch_sb_field_clean *read_superblock_clean(struct bch_fs *c)
                        GFP_KERNEL);
        if (!clean) {
                mutex_unlock(&c->sb_lock);
-               return ERR_PTR(-ENOMEM);
+               return ERR_PTR(-BCH_ERR_ENOMEM_read_superblock_clean);
        }
 
        ret = bch2_sb_clean_validate_late(c, clean, READ);
@@ -922,6 +961,20 @@ fsck_err:
        return ERR_PTR(ret);
 }
 
+static bool btree_id_is_alloc(enum btree_id id)
+{
+       switch (id) {
+       case BTREE_ID_alloc:
+       case BTREE_ID_backpointers:
+       case BTREE_ID_need_discard:
+       case BTREE_ID_freespace:
+       case BTREE_ID_bucket_gens:
+               return true;
+       default:
+               return false;
+       }
+}
+
 static int read_btree_roots(struct bch_fs *c)
 {
        unsigned i;
@@ -933,14 +986,14 @@ static int read_btree_roots(struct bch_fs *c)
                if (!r->alive)
                        continue;
 
-               if (i == BTREE_ID_alloc &&
+               if (btree_id_is_alloc(i) &&
                    c->opts.reconstruct_alloc) {
                        c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                        continue;
                }
 
                if (r->error) {
-                       __fsck_err(c, i == BTREE_ID_alloc
+                       __fsck_err(c, btree_id_is_alloc(i)
                                   ? FSCK_CAN_IGNORE : 0,
                                   "invalid btree root %s",
                                   bch2_btree_ids[i]);
@@ -950,75 +1003,85 @@ static int read_btree_roots(struct bch_fs *c)
 
                ret = bch2_btree_root_read(c, i, &r->key, r->level);
                if (ret) {
-                       __fsck_err(c, i == BTREE_ID_alloc
+                       __fsck_err(c,
+                                  btree_id_is_alloc(i)
                                   ? FSCK_CAN_IGNORE : 0,
                                   "error reading btree root %s",
                                   bch2_btree_ids[i]);
-                       if (i == BTREE_ID_alloc)
+                       if (btree_id_is_alloc(i))
                                c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                }
        }
 
-       for (i = 0; i < BTREE_ID_NR; i++)
-               if (!c->btree_roots[i].b)
+       for (i = 0; i < BTREE_ID_NR; i++) {
+               struct btree_root *r = &c->btree_roots[i];
+
+               if (!r->b) {
+                       r->alive = false;
+                       r->level = 0;
                        bch2_btree_root_alloc(c, i);
+               }
+       }
 fsck_err:
        return ret;
 }
 
 static int bch2_fs_initialize_subvolumes(struct bch_fs *c)
 {
-       struct bkey_i_snapshot  root_snapshot;
-       struct bkey_i_subvolume root_volume;
+       struct bkey_i_snapshot_tree     root_tree;
+       struct bkey_i_snapshot          root_snapshot;
+       struct bkey_i_subvolume         root_volume;
        int ret;
 
+       bkey_snapshot_tree_init(&root_tree.k_i);
+       root_tree.k.p.offset            = 1;
+       root_tree.v.master_subvol       = cpu_to_le32(1);
+       root_tree.v.root_snapshot       = cpu_to_le32(U32_MAX);
+
        bkey_snapshot_init(&root_snapshot.k_i);
        root_snapshot.k.p.offset = U32_MAX;
        root_snapshot.v.flags   = 0;
        root_snapshot.v.parent  = 0;
        root_snapshot.v.subvol  = BCACHEFS_ROOT_SUBVOL;
-       root_snapshot.v.pad     = 0;
+       root_snapshot.v.tree    = cpu_to_le32(1);
        SET_BCH_SNAPSHOT_SUBVOL(&root_snapshot.v, true);
 
-       ret = bch2_btree_insert(c, BTREE_ID_snapshots,
-                               &root_snapshot.k_i,
-                               NULL, NULL, 0);
-       if (ret)
-               return ret;
-
-
        bkey_subvolume_init(&root_volume.k_i);
        root_volume.k.p.offset = BCACHEFS_ROOT_SUBVOL;
        root_volume.v.flags     = 0;
        root_volume.v.snapshot  = cpu_to_le32(U32_MAX);
        root_volume.v.inode     = cpu_to_le64(BCACHEFS_ROOT_INO);
 
-       ret = bch2_btree_insert(c, BTREE_ID_subvolumes,
-                               &root_volume.k_i,
-                               NULL, NULL, 0);
+       ret =   bch2_btree_insert(c, BTREE_ID_snapshot_trees,
+                                 &root_tree.k_i,
+                                 NULL, NULL, 0) ?:
+               bch2_btree_insert(c, BTREE_ID_snapshots,
+                                 &root_snapshot.k_i,
+                                 NULL, NULL, 0) ?:
+               bch2_btree_insert(c, BTREE_ID_subvolumes,
+                                 &root_volume.k_i,
+                                 NULL, NULL, 0);
        if (ret)
-               return ret;
-
-       return 0;
+               bch_err_fn(c, ret);
+       return ret;
 }
 
-static int bch2_fs_upgrade_for_subvolumes(struct btree_trans *trans)
+static int __bch2_fs_upgrade_for_subvolumes(struct btree_trans *trans)
 {
        struct btree_iter iter;
        struct bkey_s_c k;
        struct bch_inode_unpacked inode;
        int ret;
 
-       bch2_trans_iter_init(trans, &iter, BTREE_ID_inodes,
-                            SPOS(0, BCACHEFS_ROOT_INO, U32_MAX), 0);
-       k = bch2_btree_iter_peek_slot(&iter);
+       k = bch2_bkey_get_iter(trans, &iter, BTREE_ID_inodes,
+                              SPOS(0, BCACHEFS_ROOT_INO, U32_MAX), 0);
        ret = bkey_err(k);
        if (ret)
-               goto err;
+               return ret;
 
        if (!bkey_is_inode(k.k)) {
                bch_err(trans->c, "root inode not found");
-               ret = -ENOENT;
+               ret = -BCH_ERR_ENOENT_inode;
                goto err;
        }
 
@@ -1033,12 +1096,22 @@ err:
        return ret;
 }
 
+/* set bi_subvol on root inode */
+noinline_for_stack
+static int bch2_fs_upgrade_for_subvolumes(struct bch_fs *c)
+{
+       int ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_LAZY_RW,
+                               __bch2_fs_upgrade_for_subvolumes(&trans));
+       if (ret)
+               bch_err_fn(c, ret);
+       return ret;
+}
+
 int bch2_fs_recovery(struct bch_fs *c)
 {
-       const char *err = "cannot allocate memory";
        struct bch_sb_field_clean *clean = NULL;
        struct jset *last_journal_entry = NULL;
-       u64 blacklist_seq, journal_seq;
+       u64 last_seq, blacklist_seq, journal_seq;
        bool write_sb = false;
        int ret = 0;
 
@@ -1073,27 +1146,25 @@ int bch2_fs_recovery(struct bch_fs *c)
                goto err;
        }
 
-       if (!(c->sb.features & (1ULL << BCH_FEATURE_alloc_v2))) {
-               bch_info(c, "alloc_v2 feature bit not set, fsck required");
-               c->opts.fsck = true;
-               c->opts.fix_errors = FSCK_OPT_YES;
-       }
-
-       if (!c->replicas.entries ||
-           c->opts.rebuild_replicas) {
-               bch_info(c, "building replicas info");
-               set_bit(BCH_FS_REBUILD_REPLICAS, &c->flags);
-       }
-
        if (!c->opts.nochanges) {
-               if (c->sb.version < bcachefs_metadata_version_new_data_types) {
-                       bch_info(c, "version prior to new_data_types, upgrade and fsck required");
+               if (c->sb.version < bcachefs_metadata_required_upgrade_below) {
+                       bch_info(c, "version %s (%u) prior to %s (%u), upgrade and fsck required",
+                                bch2_metadata_versions[c->sb.version],
+                                c->sb.version,
+                                bch2_metadata_versions[bcachefs_metadata_required_upgrade_below],
+                                bcachefs_metadata_required_upgrade_below);
                        c->opts.version_upgrade = true;
                        c->opts.fsck            = true;
                        c->opts.fix_errors      = FSCK_OPT_YES;
                }
        }
 
+       if (c->opts.fsck && c->opts.norecovery) {
+               bch_err(c, "cannot select both norecovery and fsck");
+               ret = -EINVAL;
+               goto err;
+       }
+
        ret = bch2_blacklist_table_initialize(c);
        if (ret) {
                bch_err(c, "error initializing blacklist table");
@@ -1105,10 +1176,17 @@ int bch2_fs_recovery(struct bch_fs *c)
                struct journal_replay **i;
 
                bch_verbose(c, "starting journal read");
-               ret = bch2_journal_read(c, &blacklist_seq, &journal_seq);
+               ret = bch2_journal_read(c, &last_seq, &blacklist_seq, &journal_seq);
                if (ret)
                        goto err;
 
+               /*
+                * note: cmd_list_journal needs the blacklist table fully up to date so
+                * it can asterisk ignored journal entries:
+                */
+               if (c->opts.read_journal_only)
+                       goto out;
+
                genradix_for_each_reverse(&c->journal_entries, iter, i)
                        if (*i && !(*i)->ignore) {
                                last_journal_entry = &(*i)->j;
@@ -1126,7 +1204,15 @@ int bch2_fs_recovery(struct bch_fs *c)
 
                if (!last_journal_entry) {
                        fsck_err_on(!c->sb.clean, c, "no journal entries found");
-                       goto use_clean;
+                       if (clean)
+                               goto use_clean;
+
+                       genradix_for_each_reverse(&c->journal_entries, iter, i)
+                               if (*i) {
+                                       last_journal_entry = &(*i)->j;
+                                       (*i)->ignore = false;
+                                       break;
+                               }
                }
 
                ret = journal_keys_sort(c);
@@ -1143,16 +1229,13 @@ int bch2_fs_recovery(struct bch_fs *c)
 use_clean:
                if (!clean) {
                        bch_err(c, "no superblock clean section found");
-                       ret = BCH_FSCK_REPAIR_IMPOSSIBLE;
+                       ret = -BCH_ERR_fsck_repair_impossible;
                        goto err;
 
                }
                blacklist_seq = journal_seq = le64_to_cpu(clean->journal_seq) + 1;
        }
 
-       if (c->opts.read_journal_only)
-               goto out;
-
        if (c->opts.reconstruct_alloc) {
                c->sb.compat &= ~(1ULL << BCH_COMPAT_alloc_info);
                drop_alloc_keys(&c->journal_keys);
@@ -1175,7 +1258,9 @@ use_clean:
                journal_seq += 8;
 
        if (blacklist_seq != journal_seq) {
-               ret = bch2_journal_seq_blacklist_add(c,
+               ret =   bch2_journal_log_msg(c, "blacklisting entries %llu-%llu",
+                                            blacklist_seq, journal_seq) ?:
+                       bch2_journal_seq_blacklist_add(c,
                                        blacklist_seq, journal_seq);
                if (ret) {
                        bch_err(c, "error creating new journal seq blacklist entry");
@@ -1183,143 +1268,161 @@ use_clean:
                }
        }
 
-       ret = bch2_fs_journal_start(&c->journal, journal_seq);
+       ret =   bch2_journal_log_msg(c, "starting journal at entry %llu, replaying %llu-%llu",
+                                    journal_seq, last_seq, blacklist_seq - 1) ?:
+               bch2_fs_journal_start(&c->journal, journal_seq);
        if (ret)
                goto err;
 
+       if (c->opts.reconstruct_alloc)
+               bch2_journal_log_msg(c, "dropping alloc info");
+
+       /*
+        * Skip past versions that might have possibly been used (as nonces),
+        * but hadn't had their pointers written:
+        */
+       if (c->sb.encryption_type && !c->sb.clean)
+               atomic64_add(1 << 16, &c->key_version);
+
        ret = read_btree_roots(c);
        if (ret)
                goto err;
 
        bch_verbose(c, "starting alloc read");
-       err = "error reading allocation information";
-
        down_read(&c->gc_lock);
-       ret = bch2_alloc_read(c);
+       ret = c->sb.version < bcachefs_metadata_version_bucket_gens
+               ? bch2_alloc_read(c)
+               : bch2_bucket_gens_read(c);
        up_read(&c->gc_lock);
-
        if (ret)
                goto err;
        bch_verbose(c, "alloc read done");
 
        bch_verbose(c, "starting stripes_read");
-       err = "error reading stripes";
        ret = bch2_stripes_read(c);
        if (ret)
                goto err;
        bch_verbose(c, "stripes_read done");
 
-       /*
-        * If we're not running fsck, this ensures bch2_fsck_err() calls are
-        * instead interpreted as bch2_inconsistent_err() calls:
-        */
-       if (!c->opts.fsck)
-               set_bit(BCH_FS_FSCK_DONE, &c->flags);
+       if (c->sb.version < bcachefs_metadata_version_snapshot_2) {
+               ret = bch2_fs_initialize_subvolumes(c);
+               if (ret)
+                       goto err;
+       }
+
+       bch_verbose(c, "reading snapshots table");
+       ret = bch2_fs_snapshots_start(c);
+       if (ret)
+               goto err;
+       bch_verbose(c, "reading snapshots done");
 
-       if (c->opts.fsck ||
-           !(c->sb.compat & (1ULL << BCH_COMPAT_alloc_info)) ||
-           !(c->sb.compat & (1ULL << BCH_COMPAT_alloc_metadata)) ||
-           test_bit(BCH_FS_REBUILD_REPLICAS, &c->flags)) {
+       if (c->opts.fsck) {
                bool metadata_only = c->opts.norecovery;
 
                bch_info(c, "checking allocations");
-               err = "error checking allocations";
                ret = bch2_gc(c, true, metadata_only);
                if (ret)
                        goto err;
                bch_verbose(c, "done checking allocations");
-       }
 
-       if (c->opts.fsck) {
-               bch_info(c, "checking need_discard and freespace btrees");
-               err = "error checking need_discard and freespace btrees";
-               ret = bch2_check_alloc_info(c);
+               set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
+
+               set_bit(BCH_FS_MAY_GO_RW, &c->flags);
+
+               bch_info(c, "starting journal replay, %zu keys", c->journal_keys.nr);
+               ret = bch2_journal_replay(c, last_seq, blacklist_seq - 1);
                if (ret)
                        goto err;
+               if (c->opts.verbose || !c->sb.clean)
+                       bch_info(c, "journal replay done");
 
-               ret = bch2_check_lrus(c, true);
+               bch_info(c, "checking need_discard and freespace btrees");
+               ret = bch2_check_alloc_info(c);
                if (ret)
                        goto err;
                bch_verbose(c, "done checking need_discard and freespace btrees");
-       }
 
-       bch2_stripes_heap_start(c);
+               set_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags);
 
-       clear_bit(BCH_FS_REBUILD_REPLICAS, &c->flags);
-       set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
-       set_bit(BCH_FS_MAY_GO_RW, &c->flags);
-
-       /*
-        * Skip past versions that might have possibly been used (as nonces),
-        * but hadn't had their pointers written:
-        */
-       if (c->sb.encryption_type && !c->sb.clean)
-               atomic64_add(1 << 16, &c->key_version);
-
-       if (c->opts.norecovery)
-               goto out;
+               bch_info(c, "checking lrus");
+               ret = bch2_check_lrus(c);
+               if (ret)
+                       goto err;
+               bch_verbose(c, "done checking lrus");
+               set_bit(BCH_FS_CHECK_LRUS_DONE, &c->flags);
 
-       bch_verbose(c, "starting journal replay, %zu keys", c->journal_keys.nr);
-       err = "journal replay failed";
-       ret = bch2_journal_replay(c);
-       if (ret)
-               goto err;
-       if (c->opts.verbose || !c->sb.clean)
-               bch_info(c, "journal replay done");
+               bch_info(c, "checking backpointers to alloc keys");
+               ret = bch2_check_btree_backpointers(c);
+               if (ret)
+                       goto err;
+               bch_verbose(c, "done checking backpointers to alloc keys");
 
-       err = "error initializing freespace";
-       ret = bch2_fs_freespace_init(c);
-       if (ret)
-               goto err;
+               bch_info(c, "checking backpointers to extents");
+               ret = bch2_check_backpointers_to_extents(c);
+               if (ret)
+                       goto err;
+               bch_verbose(c, "done checking backpointers to extents");
 
-       if (c->opts.fsck) {
-               bch_info(c, "checking alloc to lru refs");
-               err = "error checking alloc to lru refs";
-               ret = bch2_check_alloc_to_lru_refs(c);
+               bch_info(c, "checking extents to backpointers");
+               ret = bch2_check_extents_to_backpointers(c);
                if (ret)
                        goto err;
+               bch_verbose(c, "done checking extents to backpointers");
+               set_bit(BCH_FS_CHECK_BACKPOINTERS_DONE, &c->flags);
 
-               ret = bch2_check_lrus(c, true);
+               bch_info(c, "checking alloc to lru refs");
+               ret = bch2_check_alloc_to_lru_refs(c);
                if (ret)
                        goto err;
                bch_verbose(c, "done checking alloc to lru refs");
-       }
+               set_bit(BCH_FS_CHECK_ALLOC_TO_LRU_REFS_DONE, &c->flags);
+       } else {
+               set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
+               set_bit(BCH_FS_CHECK_ALLOC_DONE, &c->flags);
+               set_bit(BCH_FS_CHECK_LRUS_DONE, &c->flags);
+               set_bit(BCH_FS_CHECK_BACKPOINTERS_DONE, &c->flags);
+               set_bit(BCH_FS_CHECK_ALLOC_TO_LRU_REFS_DONE, &c->flags);
+               set_bit(BCH_FS_FSCK_DONE, &c->flags);
 
-       if (c->sb.version < bcachefs_metadata_version_snapshot_2) {
-               bch2_fs_lazy_rw(c);
+               if (c->opts.norecovery)
+                       goto out;
 
-               err = "error creating root snapshot node";
-               ret = bch2_fs_initialize_subvolumes(c);
+               set_bit(BCH_FS_MAY_GO_RW, &c->flags);
+
+               bch_verbose(c, "starting journal replay, %zu keys", c->journal_keys.nr);
+               ret = bch2_journal_replay(c, last_seq, blacklist_seq - 1);
                if (ret)
                        goto err;
+               if (c->opts.verbose || !c->sb.clean)
+                       bch_info(c, "journal replay done");
        }
 
-       bch_verbose(c, "reading snapshots table");
-       err = "error reading snapshots table";
-       ret = bch2_fs_snapshots_start(c);
+       ret = bch2_fs_freespace_init(c);
        if (ret)
                goto err;
-       bch_verbose(c, "reading snapshots done");
+
+       if (c->sb.version < bcachefs_metadata_version_bucket_gens &&
+           c->opts.version_upgrade) {
+               bch_info(c, "initializing bucket_gens");
+               ret = bch2_bucket_gens_init(c);
+               if (ret)
+                       goto err;
+               bch_verbose(c, "bucket_gens init done");
+       }
 
        if (c->sb.version < bcachefs_metadata_version_snapshot_2) {
-               /* set bi_subvol on root inode */
-               err = "error upgrade root inode for subvolumes";
-               ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_LAZY_RW,
-                                   bch2_fs_upgrade_for_subvolumes(&trans));
+               ret = bch2_fs_upgrade_for_subvolumes(c);
                if (ret)
                        goto err;
        }
 
        if (c->opts.fsck) {
-               bch_info(c, "starting fsck");
-               err = "error in fsck";
                ret = bch2_fsck_full(c);
                if (ret)
                        goto err;
                bch_verbose(c, "fsck done");
        } else if (!c->sb.clean) {
                bch_verbose(c, "checking for deleted inodes");
-               err = "error in recovery";
                ret = bch2_fsck_walk_inodes_only(c);
                if (ret)
                        goto err;
@@ -1363,14 +1466,11 @@ use_clean:
            le16_to_cpu(c->sb.version_min) < bcachefs_metadata_version_btree_ptr_sectors_written) {
                struct bch_move_stats stats;
 
-               bch_move_stats_init(&stats, "recovery");
+               bch2_move_stats_init(&stats, "recovery");
 
                bch_info(c, "scanning for old btree nodes");
-               ret = bch2_fs_read_write(c);
-               if (ret)
-                       goto err;
-
-               ret = bch2_scan_old_btree_nodes(c, &stats);
+               ret =   bch2_fs_read_write(c) ?:
+                       bch2_scan_old_btree_nodes(c, &stats);
                if (ret)
                        goto err;
                bch_info(c, "scanning for old btree nodes done");
@@ -1385,15 +1485,22 @@ out:
        set_bit(BCH_FS_FSCK_DONE, &c->flags);
        bch2_flush_fsck_errs(c);
 
-       if (!c->opts.keep_journal) {
+       if (!c->opts.keep_journal &&
+           test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)) {
                bch2_journal_keys_free(&c->journal_keys);
                bch2_journal_entries_free(c);
        }
        kfree(clean);
+
+       if (!ret && test_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags)) {
+               bch2_fs_read_write_early(c);
+               bch2_delete_dead_snapshots_async(c);
+       }
+
        if (ret)
-               bch_err(c, "Error in recovery: %s (%i)", err, ret);
+               bch_err_fn(c, ret);
        else
-               bch_verbose(c, "ret %i", ret);
+               bch_verbose(c, "ret %s", bch2_err_str(ret));
        return ret;
 err:
 fsck_err:
@@ -1406,7 +1513,6 @@ int bch2_fs_initialize(struct bch_fs *c)
        struct bch_inode_unpacked root_inode, lostfound_inode;
        struct bkey_inode_buf packed_inode;
        struct qstr lostfound = QSTR("lost+found");
-       const char *err = "cannot allocate memory";
        struct bch_dev *ca;
        unsigned i;
        int ret;
@@ -1417,6 +1523,9 @@ int bch2_fs_initialize(struct bch_fs *c)
        c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_extents_above_btree_updates_done);
        c->disk_sb.sb->compat[0] |= cpu_to_le64(1ULL << BCH_COMPAT_bformat_overflow_done);
 
+       if (c->sb.version < bcachefs_metadata_version_inode_v3)
+               c->opts.version_upgrade = true;
+
        if (c->opts.version_upgrade) {
                c->disk_sb.sb->version = cpu_to_le16(bcachefs_metadata_version_current);
                c->disk_sb.sb->features[0] |= cpu_to_le64(BCH_SB_FEATURES_ALL);
@@ -1425,6 +1534,9 @@ int bch2_fs_initialize(struct bch_fs *c)
        mutex_unlock(&c->sb_lock);
 
        set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags);
+       set_bit(BCH_FS_CHECK_LRUS_DONE, &c->flags);
+       set_bit(BCH_FS_CHECK_BACKPOINTERS_DONE, &c->flags);
+       set_bit(BCH_FS_CHECK_ALLOC_TO_LRU_REFS_DONE, &c->flags);
        set_bit(BCH_FS_MAY_GO_RW, &c->flags);
        set_bit(BCH_FS_FSCK_DONE, &c->flags);
 
@@ -1434,7 +1546,6 @@ int bch2_fs_initialize(struct bch_fs *c)
        for_each_online_member(ca, c, i)
                bch2_dev_usage_init(ca);
 
-       err = "unable to allocate journal buckets";
        for_each_online_member(ca, c, i) {
                ret = bch2_dev_journal_alloc(ca);
                if (ret) {
@@ -1450,7 +1561,6 @@ int bch2_fs_initialize(struct bch_fs *c)
        bch2_fs_journal_start(&c->journal, 1);
        bch2_journal_set_replay_done(&c->journal);
 
-       err = "error going read-write";
        ret = bch2_fs_read_write_early(c);
        if (ret)
                goto err;
@@ -1460,7 +1570,6 @@ int bch2_fs_initialize(struct bch_fs *c)
         * btree updates
         */
        bch_verbose(c, "marking superblocks");
-       err = "error marking superblock and journal";
        for_each_member_device(ca, c, i) {
                ret = bch2_trans_mark_dev_sb(c, ca);
                if (ret) {
@@ -1471,41 +1580,36 @@ int bch2_fs_initialize(struct bch_fs *c)
                ca->new_fs_bucket_idx = 0;
        }
 
-       bch_verbose(c, "initializing freespace");
-       err = "error initializing freespace";
        ret = bch2_fs_freespace_init(c);
        if (ret)
                goto err;
 
-       err = "error creating root snapshot node";
        ret = bch2_fs_initialize_subvolumes(c);
        if (ret)
                goto err;
 
        bch_verbose(c, "reading snapshots table");
-       err = "error reading snapshots table";
        ret = bch2_fs_snapshots_start(c);
        if (ret)
                goto err;
        bch_verbose(c, "reading snapshots done");
 
-       bch2_inode_init(c, &root_inode, 0, 0,
-                       S_IFDIR|S_IRWXU|S_IRUGO|S_IXUGO, 0, NULL);
+       bch2_inode_init(c, &root_inode, 0, 0, S_IFDIR|0755, 0, NULL);
        root_inode.bi_inum      = BCACHEFS_ROOT_INO;
        root_inode.bi_subvol    = BCACHEFS_ROOT_SUBVOL;
-       bch2_inode_pack(c, &packed_inode, &root_inode);
+       bch2_inode_pack(&packed_inode, &root_inode);
        packed_inode.inode.k.p.snapshot = U32_MAX;
 
-       err = "error creating root directory";
        ret = bch2_btree_insert(c, BTREE_ID_inodes,
                                &packed_inode.inode.k_i,
                                NULL, NULL, 0);
-       if (ret)
+       if (ret) {
+               bch_err_msg(c, ret, "creating root directory");
                goto err;
+       }
 
        bch2_inode_init_early(c, &lostfound_inode);
 
-       err = "error creating lost+found";
        ret = bch2_trans_do(c, NULL, NULL, 0,
                bch2_create_trans(&trans,
                                  BCACHEFS_ROOT_SUBVOL_INUM,
@@ -1514,7 +1618,7 @@ int bch2_fs_initialize(struct bch_fs *c)
                                  0, 0, S_IFDIR|0700, 0,
                                  NULL, NULL, (subvol_inum) { 0 }, 0));
        if (ret) {
-               bch_err(c, "error creating lost+found");
+               bch_err_msg(c, ret, "creating lost+found");
                goto err;
        }
 
@@ -1524,10 +1628,11 @@ int bch2_fs_initialize(struct bch_fs *c)
                        goto err;
        }
 
-       err = "error writing first journal entry";
        ret = bch2_journal_flush(&c->journal);
-       if (ret)
+       if (ret) {
+               bch_err_msg(c, ret, "writing first journal entry");
                goto err;
+       }
 
        mutex_lock(&c->sb_lock);
        SET_BCH_SB_INITIALIZED(c->disk_sb.sb, true);
@@ -1538,6 +1643,6 @@ int bch2_fs_initialize(struct bch_fs *c)
 
        return 0;
 err:
-       pr_err("Error initializing new filesystem: %s (%i)", err, ret);
+       bch_err_fn(ca, ret);
        return ret;
 }